Tiffany is 8 years older than Gabriela. Fourteen years ago, Tiffany was 5 times as old as Gabriela. How old is Gabriela now?
Solution: We can use the given information to write down two equations that describe the ages of Tiffany and Gabriela. Let Tiffany's current age be $t$ and Gabriela's current age be $g$ The information in the first sentence can be expressed in the following equation: $t = g + 8$ Fourteen years ago, Tiffany was $t - 14$ years old, and Gabriela was $g - 14$ years old. The information in the second sentence can be expressed in the following equation: $t - 14 = 5(g - 14)$ Now we have two independent equations, and we can solve for our two unknowns. Because we are looking for $g$ , it might be easiest to use our first equation for $t$ and substitute it into our second equation. Our first equation is: $t = g + 8$ . Substituting this into our second equation, we get the equation: $(g + 8)$ $-$ $14 = 5(g - 14)$ which combines the information about $g$ from both of our original equations. Simplifying both sides of this equation, we get: $g - 6 = 5 g - 70$ Solving for $g$ , we get: $4 g = 64$ $g = 16$.